Twenty-three field coils, working in concert from the surface of Bilana III, were the source behind the creation of a soliton wave, the first step towards "warp without warp drive." (TNG: "New Ground")

In order to keep a transportersignal lock on an individual, and counteract the effects of a subspace transporter system, it is necessary to tie a ship's subspace field coils into the transporter system. This tie in can be used for implementing a subspace transport, by means of using the transporter system to shunt something through subspace. (TNG: "Bloodlines")